The invention relates to equipment for recovering and preparing for reuse the scrap metal produced in machining operations. Basically this material consists of chips and borings and shavings produced by such machines as planers, automatic screw machines, boring machines, lathes, milling machines and saws. This material is normally coated with the lubricant used in the machining process. The material frequently has a wide range of sizes and shapes. Some of the material is in the form of chips and small pieces requiring no size reduction. Significant quantities of the material consist of elongated spirals frequently simulating coiled springs. These latter machine turnings tend to become intermeshed producing a bulky, springy, snarled and entangling matrix which must be reduced to small chips to permit efficient extraction of the oil and also to reduce the bulk.
The common method of reducing this type of material to small chips or pieces is to pass it through a hammermill or a crusher which reduces these materials to a reasonably uniform small chip or short length. A number of crushers are available, employing a variety of reduction means. So far as is known, all of this equipment is designed for vertical feed, that is, the material to be crushed is fed from the top, passes down through the crusher and the processed material is discharged at the bottom.
If the material, as received at the crusher, consisted entirely of chips, machine turnings, boring and the like, the problem of effectively crushing and reducing the metallic materials to a reasonably uniform, small size would be relatively simple. However, normally these materials, as received at the crusher, contain a substantial quantity of large pieces or chunks which are not the product of machining of various metal parts. It is these components of the material which causes substantial difficulty. These include such items as ends of bar stock, bolts and steel parts from the machines on which the materials have been machined, broken and scrap parts. These materials are not suitable for processing in the crushers. When such materials enter the crusher, they become jammed in the teeth or between the rolls of the crusher, causing damage and, in some cases, stalling the crusher. When this happens, even if the crusher is not damaged, it is necessary to stop the equipment and clean out the crusher to free it for further operation. This is an expensive and time consuming procedure and materially reduces the economic efficiency of reclaiming the scrap from machining operations. Heretofore, there has been no successful means by which this problem could be eliminated despite the fact that it has plagued the machine turnings recovery field for a number of years.